Automatic ice maker control means



Nov. 21, 1961 H. P. HARLE AUTOMATIC ICE MAKER CONTROL MEANS 2Sheets-Sheet 1 Filed Sept. 14, 1960 INVEN TOR. HAROLD F'. HARLE H 15ATTORNEY Nov. 21, 1961 H. P. HARLE AUTOMATIC ICE MAKER CONTROL MEANS 2Sheets-Sheet 2 F i G. 3

Filed Sept. 14, 1960 FIGZ INVENTOR.

a HAROLD P. HARLE HIS ATTORNEY Patented Nov. 21, 1961 free 3,009,330AUTOMATIC ICE MAKER CONTROL MEANS Harold P. Harte, Louisville, Ky.,assignor to General Electric Company, a corporation of New York FiledSept. 14, 1960, Ser. No. 55,954 2 (Ilaiins. (til. 62-437) The presentinvention relates to an automatic ice maker and is more particularlyconcerned with an improved control means for an ice maker of the typeadapted to be incorporated in a domestic or household refrigerator.

The invention relates particularly to the general type of ice makerincluding a mold in which a charge of water is frozen, means for heatingthe mold to release the ice pieces formed therein, means for removingice pieces formed in the mold comprising one or more pivoting transferelements which are frozen into engagement with the ice pieces duringeach freezing cycle and are movable from their normal positions withinthe mold to an ice piece discharge position outside the mold and watersupply means for thereafter introducing another charge of water into themold. An ice maker of this type in which movable dividers or partitionsserve as transfer elements for harvesting the ice pieces is describedand claimed in the copending application Serial No. 813,790 (now Patent2,970,453) filed May 18, 1959 in the names of Harold P. Harle, StephenBalogh and Henry I. Lowenthal and assigned to the same assignee as thepresent invention.

The present invention has as its principal object the provision of animproved control means for eifecting the automatic operation of an icemaker.

Another and more specific object of the invention is to provide anautomatic ice maker of this type including improved control means forstopping the operation of the ice maker when the required quantity ofice has been manufactured.

Further objects and advantages of the invention will become apparentfrom the following description, reference being made to the accompanyingdrawing in which:

FIG. 1 is an elevational view, partly in section, of an ice makerincluding an embodiment of the present invention;

FIG. 2 is a sectional view of the ice maker along line 2-2 of FIG. 1;

FIGS is a sectional view of the ice maker along line 3-3 of FIG. 1;

FIG. 4 is a sectional view of the ice mold taken generally along line 44of FIG. 1 but showing the movable dividers in a discharge position; and

FIG. 5 is a wiring diagram of the improved electrical control systememployed for the automatic operation of the ice maker in accordance withthe present invention.

With reference to FIG. 1 of the drawing, there is illustrated an icemaker designed to be suspended from the top wall 1 of the lowtemperature or freezing compartment 2 of a household refrigerator. Thecontents of the compartment 2 including the ice maker are maintained atthe below freezing temperatures by air circulated over a low temperatureevaporator (not shown) so that the ice maker can be mounted in thecompartment out of direct contact with an evaporator unit. Alsopositioned within the compartment and below the ice maker is an icereceptacle or bin 3 in which ice pieces 4 discharged from the ice makerare stored at freezing temperatures.

Referring now to FIGS. 1 and 2 of the drawing, the ice maker includes anelongated ice mold '5 comprising end walls 7 and side walls 8 and 9forming a substantially rectangular mold cavity which is divided into aplurality of sections by fixed, full width dividers or partitions 10extending transversely of the mold cavity. Each of these sections is inturn divided into adjacent interconnected compartments 11 by movabledividers 12 arranged between the fixed dividers. The mold properincluding the end walls '7, the side walls 8 and 9, the dividers 10 anda bottom wall 14 are composed of metal and preferably comprise a unitarydie cast structure.

The movable dividers 12 which function as transfer elements for removingice pieces from the mold are composed of a low heat conducting flexiblematerial such as a plastic material, thin stainless steel or the likeand are each mounted on a shaft 18 rotatably supported above thevertical mold side wall 8. In order that the movable dividers 12 canpivot about the aXis of the shaft 18 from a position within the mold asillustrated in FIG. 1 to a discharge position along one side of the moldas illustrated in FIG. 4, the mold side wall 9 opposite the shaft 18slopes outwardly and is of a generally concave configuration While thecooperating side edge 19 of each of the movable dividers is similarlyshaped. To provide for the flow of water from one compartment to anotherduring filling of the mold cavity, each of the fixed dividers 10includes a slot 20 adjacent the side wall 9 While the movable dividers12 have their upper edge portions 21 terminating short of the side wall9 to provide a channel or spacing similar to that provided by the slots20.

In orderto release ice pieces formed in the compartments 11 from themold walls, there is provided an electric heating element 23 extendingin the form of a loop around the bottom wall 14 below the side walls 8and 9.

U When this heating element is energized, the mold, in-

cluding its bottom wall 14, the end walls 6 and 7 and the side walls 8and 9 as well as the fixed partitions 10, becomes sufficiently warm tomelt the bond between the mold surfaces and the ice pieces. However,since the movable dividers 12 are composed of a material of lower heatconductivity than the mold, there isinsufiicient warming of thesemembers to melt the ice bond. These movable dividers, upon rotation outof the mold, then serve as transfer elements by means of which icepieces adhering thereto are removed from the mold.

While there is a natural tendency for the pieces to remain frozen to thelow heat conductivity material for a longer period of time than to thedirectly heated mold, in order to morepositively assure transportationof the ice pieces from the mold and over the mold side wall 8 duringpivotal movement of the movable elements 12, these elements arepreferably also provided with additional means for anchoring the icepieces to the dividers. In the illustrated embodiment of the invention,the movable dividers 12 have fins 24 along both sides of the rear edgesthereof, that is along the edges adjacent the shaft 18, and notches 25in the. opposite edges.

Once the bond between the ice mold proper and the ice pieces has beenbroken or thawed, the movable dividers 12 can be pivoted upwardly andoutwardly from the mold by rotation of the shaft 18 to a dischargeposition as shown in FIG. 2 in which the ice pieces come into contactwith a plurality of spaced bumpers 26 suitably supported along the sidewall 8 of the mold. As will be seen in FIG. 1 of the drawing thesebumpers are opposite the fixed, dividers l0 and are wide, enough tooverlap thecompartments ll on each side of the fixed dividers. When theice pieces contact the surfaces of bumpers, movement of the ice piecesis stopped and the continued movement of the dividers causes theicepieces to peel away from the dividers and drop into the receptacle 3provided below the mold. I Control and power mechanism for effecting andcontrolling the operation of the ice maker is generally housed in ahousingZS secured to one end of the mold 5. The power mechanism includesa motor 29 diagrammatically illustrated in FIG. of the drawing, themotor and a suitable speed reducing gear train forming a drive mechanismgenerally shown in broken lines and indicated by the numeral 30 in FIG.1 of the drawing. The shaft 18 is rotatably mounted in a bearing 31adjacent the mold end wall 7 and a bearing (not shown) in the front wall32 of the housing. A pawl assembly 33 shown in FIG. 2 is connected tothe end of the shaft 18 extending into into the housing and an arm 34-connected to the drive shaft 35 forming part of the drive mechanism 36provides means for connecting the motor to the shaft to rotate the shaft18 after certain control switching functions have been effected by themotor. To this end, the arm 34 is arranged for delayed engagement withthe pawl 37 after initial energization of the motor. The pawl 37 ispivotally supported on that assembly as illustrated in FIG. 2 of thedrawing in such a position that after further rotation of the shaft 18through a predetermined number of degrees, a projection 38 on the wall32 causes disengagement of the pawl from the arm and allows the motor tocontinue rotating in the same direction while a return spring 40 onshaft 18 causes the shaft to rotate in the opposite direction and returnthe dividers to the mold.

The illustrated water supply means, which is more fully described andclaimed in my copending application S.N. 25,432 filed April 29, 1960 andassigned to the same assignee as the present invention, includes afiller tube 41 connected through a normally closed solenoid valve 42 toa suitable source of water supply. When the solenoid valve is energizedto open the valve, water is supplied to the mold from the outlet end ofthe tube 41, this charge of water flowing downwardly into the mold overa baffle 43 supported on the mold side wall 9. The water thus introducedinto the mold flows to the various compartments through the slots 20 andaround the dividers 12.

In order to initiate the ice harvesting cycle as soon as the waterintroduced into the mold has frozen, there is provided a motor controlcircuit including a thermal actuated switch such as a bellows operatedsingle pole double throw switch 44 diagrammatically illustrated in FIG.5 and generally housed within the housing 28. The sensing bulb componentof the switch, in the form of a capillary tube, extends through thehousing wall 32, through a plastic housing 45 along one side of the moldand then downwardly into a plastic housing 46 below one of the movabledividers 12 which is shortened to provide space for the housing. In thisposition of the sensing end 47 of the capillary tube, the switch 44 isresponsive to the temperature of the mold adjacent one of the movabledividers.

After a number of ice making cycles, the receptacle 3 becomes filledwith ice pieces. In order to stop the ice making operation when thisoccurs, the ice maker includes a U-shaped feeler arm 50 which ispivotally mounted at each end along the side 9 of the ice mold formovement between an elevated position out of the receptacle as shown inFIG. 1 and a lowered position within the receptacle. Normally, that isduring the freezing step of the ice making cycle, this arm is held inits elevated position by a motor driven cam 51. This cam is so designedthat during each ice harvesting cycle, the cam 51 releases the arm 50 sothat it can drop to its lowered position within the receptacle. If thisdrop to the lowered position is interrupted by contact of the arm withthe accumulated ice in the receptacle, a normally open switch 52operated by the feeler arm 50 remains in an open position to interruptthe ice making cycle and stop the operation of the ice maker. To obtainthis operation, the feeler arm includes within the housing 28 anextension or actuating lever 52 engaging the cam 51, the cam in turnbeing mounted on the shaft 35 driven by the motor 29. The normally openswitch 52 is designed to be closed when the feeler arm is in its loweredposition by a pin 55 carried on the actuating lever 53 as shown in FIG.3 of the drawing.

In accordance with the present invention there is provided an improvedcontrol circuitry for the automatic control of an ice maker of this typethrough a complete ice making cycle. This improved circuitry and controlmeans will be described in connection with the following considerationof the operation of the ice maker.

When the temperature sensed by the end 47 of the capillary sensing bulbreaches about 2025 F. indicating the complete freezing of the water inthe mold, the switch arm 56 of the single pole double throw switch 44moves into contact with the cold switch contact 57. This completes afirst motor energizing circuit between the supply conductors 58, 59through the cold contact 57 of the switch 44 and a first motor operatedswitch 60 which is normally closed and which is operated by a cam 61driven by the motor 29 through the shaft 35. Energizetion of the motor29 causes rotation of both of the cams 51 and 61 whereby the cam 51releases the feeler arm so that it is free to drop to its loweredposition after which the cam 61 opens the motor operated switch 60 tobreak the first motor energizing circuit. In the event that there issufiicient ice in the receptacle to prevent the feeler arm from droppingto its lowered position thereby closing switch 52, the operation of theice maker is interrupted by the opening of the switch 60 and thiscondition will continue until enough ice has been removed from thereceptacle so that the feeler arm can fall to its lower switch operatingposition. After removal of this ice or if the amount of ice accumulatedin the receptacle 3 was insuflicient to prevent the feeler arm 50 fromreaching its lowermost position, the closing of switch 52 completes asecond motor energizing circuit through switch 52 and the cold contact57 of switch 44 so that the motor continues to be energized through thissecond circuit after switch 60 is opened. The establishment of thesecond motor energizing circuit causes the cam 61 to close a heaterswitch 63 for energizing the heater 23 in order to melt the bond betweenthe ice piece and the mold.

After cam 61 has rotated to the point where the heater switch 63 closesto energize the heater 23, the drive arm 34 is designed to engage thepawl 37 for rotation of the shaft 18 as soon as the bond between the icepieces and the mold is thawed or broken. In the meantime, the motorstalls although it continues to be energized through the second motorenergizing circuit including switch 52 and the cold contact 57 of switch44.

When this ice bond is broken, the motor again operates so that thedividers and the ice pieces 4 adhering thereto are rotated out of themold into a position in which the ice pieces 4 contact the bumpers 26and are peeled from the dividers 12 for discharge into the receptacle 3.Release of pawl 37 then permits the dividers to return to the mold.During this time the mold is warmed by the heater 23 to an abovefreezing temperature. As the temperature of the sensing bulb 47 lags themold temperature due to the insulating effect of housing 46, the switch44 is designed so that when the sensing bulb temperature is about 3035F., the switch arm 56 moves into engagement with the warm contact 65whereby a third motor energizing circuit is established through theheater switch 63 and the warm contact 65 of the switch 44. One purposeof this third motor energizing circuit is to continue the energizationof the motor 29 during the latter stages of the ice making cycle, thatis after the cam 51 has rotated to a position such that it raises thefeeler arm 50 to its elevated position thus opening the switch 52 tobreak the second motor energizing circuit. By this circuitry, the icemaker operation will be interrupted at this point until such time as theswitch 44 does trip to its warm position or more specifically away fromits cold position before a new charge of water is introduced into themold. In other words, after the level switch 52 is opened the motor canonly be energized by control switch 44 in its warm position. Thisfeature prevents repeated cycling of the ice maker if the control 44 dueto any malfunction remains in its cold position.

Continued rotation of the cam 61 thereafter closes a valve energizingswitch 66 to energize and open the solenoid valve 42, the operationportion of the cam surface indicated by the numeral 68 being designed totime the open period in order to introduce a controlled quantity ofwater into the mold.

When the earns 51 and 61 have completed their rotation through onerevolution, the cam 51 has returned the feeler arm to its uppermostposition while the cam 61 has returned the switches 60, 63 and 66 totheir normal or starting positions, the opening of the heater switch 63causing both the motor and the heater 23 to be deenergized. The controland power mechanism is thereby set for the next operating cycle of theice maker when the switch arm 56 of switch 44 again engages contact 57.

While there has been shown and described a particular embodiment of thepresent invention, it will be obvious to those skilled in the art thatvarious changes and modifications may be made therein without departingfrom the invention, and it is intended by the appended claims to coverall such changes and modifications that fall within the true spirit andscope of the invention.

What I claim as new and desire to secure by Letters Patent of the UnitedStates is:

1. In an automatic ice maker comprising a mold in which water is frozeninto ice, a storage receptacle, heating means for heating said mold torelease the ice formed therein, transfer means for transferring, thereleased ice from said mold to said receptacle, a motor for operatingsaid transfer means, a feeler arm normally held in a position above saidreceptacle and movable to a level detecting position within saidreceptacle for measuring the level of ice therein, feeler arm actuatingmeans operated by said motor for releasing said arm for movement to saidlevel detecting position; electrical control means for controlling theautomatic operation of said ice maker through an ice making cycleincluding successive freezing, releasing and transferring steps and forstopping operation of said ice maker upon the accumulation of ice insaid receptacle comprising a normally open feeler arm switch, a controlswitch movable to a cold position in response to a freezing temperatureof said mold and to a warm position in response to an elevatedtemperature of said mold, a normally closed motor-operated motor switchand a normally open motor-operated heater switch, said motor switch andsaid control switch being series connected when said control switch isin its cold position to complete a first circuit for energizing saidmotor to release said feeler arm for movement to a position closing saidfeeler arm switch to thereby establish a second motor energizing circuitthrough said feeler arm switch and said control switch in its coldposition, continued energization of said motor opening said motor switchto break said first circuit and closing said heater switch, said heaterswitch and said control switch in its warm position being seriesconnected to complete a third motor energizing circuit when said moldattains an above-freezing temperature to complete the ice making cycleand return said feeler arm actuating means to its normal positionwhereby said feeler arm switch is opened to interrupt said secondcircuit.

2. In an automatic ice maker comprising a mold in which water is frozeninto ice, a storage receptacle, heating means for heating said mold torelease the ice formed therein, transfer means for transferring thereleased ice from said mold to said receptacle, a motor for operatingsaid transfer means, a feeler arm normally held in a position above saidreceptacle and movable to a level detecting position within saidreceptacle for measuring the level of ice therein, feeler arm actuatingmeans operated by said motor for releasing said arm for movement to saidlevel detecting position, electrical control means for controlling theautomatic operation of said ice maker through an ice making cycleincluding successive freezing, releasing and transferring steps and forstopping operation of said ice maker upon the accumulation of ice insaid receptacle comprising a normally open feeler arm switch, a controlswitch movable to a cold position in response to a freezing temperatureof said mold and to a warm position in response to an elevatedtemperature of said mold, a normally closed motor-operated motor switch,and a normally open motor-operated heater switch, said motor switch andsaid control switch being series connected when said control switch isin its cold position to complete a first circuit for energizing saidmotor to release said feeler arm for movement to a position closing saidfeeler arm switch to thereby establish a second motor energizing circuitthrough said feeler arm switch and said control switch in its coldposition, continued energization of said motor opening said motor switchto break said first circuit and thereafter closing said heater switch tothaw the bond between said ice and said mold, said motor being stalledwhile energized by said second circuit while the bond between the iceand mold is being thawed, said heater switch and said control switch inits warm position being series connected to complete a third motorenergizing circuit when said mold attains an abovefreezing temperatureafter removal of the ice therefrom to complete the ice making cycle, toreturn said feeler anm actuating means to its normal position wherebysaid feeler arm switch is opened to interrupt said second circuit, saidfeeler arm switch being arranged to remain open if said feeler arm isheld in an elevated position by the level of ice in said receptaclewhereby opening of said motor switch to break said first circuit stopsthe operation of said ice maker before closing of said heater switch.

References Cited in the file of this patent UNITED STATES PATENTS2,744,390 Partsch May 8, 1956 2,778,198 Heath Jan. 22, 1957 2,796,741Barton June 25, 1957 2,799,144 Barton July 16, 1957 2,955,442 LoewenthalOct. 11, 1960- 2,987,895 Loewenthal June 13, 1961

